Toe box bunches up when laced (for me, see picture above and last picture)

I've logged about 100 miles in my Saucony Kinvara 3's now, and overall I'm pretty impressed. They are extremely lightweight, and make you feel like you're practically barefoot. Unfortunately, you feel that way on trails as well. I did a 4-mile run on a fairly well-maintained gravel trail, and a few times I landed on a bigger piece of gravel and REALLY felt it. In fact, my foot was sore for several days afterwards. It's a bit hard to fault the shoe for this since it is marketed as a minimalist shoe, and providing more protection would negate most of the pros I've listed above. Nonetheless, if you frequently run on trails, even well-kept ones, you'll likely need something other than the Kinvara 3's.

The lightweight upper seems to breathe exceptionally well. I've ran several times in 100+ degree (F) heat and the shoes have been wonderful. One thing I would like to see is an upper without a tongue, like the upper on Nike Free. I'm not a huge fan of the Free's, but I do like that the upper is all one piece.

I am predominately a mid-foot striker and these shoes seemed to have been designed with me in mind. There is added "XT-900 rubber through the lateral mid-foot" providing extra cushioning and increased durability in the place you need it most. Since Saucony only added rubber to the crucial areas (the lateral mid-foot, the 9 triangular lugs on the fore-foot, and the heel) the sole is extremely flexible and conforms to your foot with every step.

The Kinvara 3's have a listed heel height of 22mm and a fore-foot height of 18mm, and I love this! I find it much easier to maintain a safe and efficient stride when tired. If you've never run in anything but traditional running shoes, make sure to take it slow for the first few weeks because your calf muscles will be screaming!

The memory foam pads in the heel actually kind of bothered me at first and seemed to rub my Achilles tendon when running. I'm not really sure how, but it stopped after about the first week and the pads seem to do exactly what Saucony says they do, "...provide a secure fit." I haven't had any problems since.

I listed durability as a con for the Kinvara 3's because I can already see signs of wear on the upper and I've only put about 100 miles on them. I doubt you can see it in the pictures I've posted, but there are small holes beginning to form where the upper meets the EVA foam sole. The wear is present in both shoes mostly near the toe box, both lateral and medial. These are the same places that many people posted about their previous Kinvara models wearing down. Surprisingly, the sole seems to be holding up rather well. I certainly had my doubts with so much exposed EVA foam, but they placed the rubber in the right spots.

Although it may sound minor, I have a problem with the upper material in the toe box bunching up when I lace up my Kinvara 3's. If I loosen the laces to the point where the toe box doesn't bunch up, my feet slide around like crazy. There is a permanent ripple down the center of the toe box from where the laces end to the toe of the shoe. It also took me a few runs to figure out what worked for me as far as lacing goes. Since the toe box is so roomy it was a bit difficult to find the sweet spot for a snug fit.

Overall, I'd give these shoes an 8 out of 10. They have turned me into a believer in minimalist style shoes, but I think there is still room for improvement. I love how lightweight they are, and also that I can feel the ground under my feet as I'm running. I would recommend these to anyone who plans to run predominately on the road or track, or is looking for a transition shoe for running barefoot or in super minimalist shoes (Merrell Trail Glove, Vibram FiveFingers Bikila, Merrell Road Glove, etc.) . Durability is still a bit of an issue, as I doubt I'll see more than 300-400 miles out of these. Anyone logging high mileage (60+ miles per week) probably can't afford to run in these since they would likely need to be replaced every couple months. Although durability is still an issue, it seems that Saucony has improved this from previous Kinvara models. Keep going Saucony! I'd love to love these shoes, but for now I just like them a lot.